Method for making covered elastic yarn



July 9, 1968 N. E. FITTON 3,391,532

METHOD FOR MAKING COVERED ELASTIC YARN Original Filed Oct. 26, 1964 2 Sheets-Sheet 1 4 a 4% 6 .g 5 mm y Y m T E 5, Ill V m M o 1 M m m! M 5 R m M 7 m M F July 9, 1968 N. E. FITTON 3,391,532

METHOD FOR MAKING COVERED ELASTIC YARN Original Filed Oct. 26, 1964 2 Sheets-Sheet 2 INVENTOR.

NORMAN E. FITTON ATTORN EY United States Patent 3,391,532 METHUD FOR MAKING COVERED ELASTIC YARN Norman Ernest Fitton, 52 Lapham St, Fall River, Mass. 02721 Griginal application Oct. 26, 1964, Ser. No. 406,466, now Patent No. 3,298,168, dated .Ian. 17, 1967. Divided and this application Sept. 1, 1966, Ser. No. 576,607

4 Claims (Cl. 57--163) ABSTRACT OF THE DISIILQSURE Method of covering an elastic thread wherein the twist in the elastic thread naturally embraces the covering yarn which is twisted in an opposite direction and with an opposite motion to the twist and to the motion imparting the twist in the elastic thread.

This application is a division of United States application Ser. No. 406,466, filed Oct. 26, 1964, now Patent No. 3,298,168, dated Ian. 17, 1967.

This invention relates to improvements in the method of and apparatus for making covered elastic yarn.

An object of the present invention is to provide an improved method and apparatus for placing a twist in a rubber core in one direction and then placing a cover of textile fibers in the form of roving spun about the rubber core in an opposite direction and the drive apparatus for economically achieving the result.

One of the more specific features of the present invention resides in the arrangement whereby the rubber core travels in a general upward direction from a rotating package to a pair of draw rolls, whereby a twist is imparted to the rubber core; at the draw rolls the rubber core is met by roving and the rubber core and roving are spun together in a direction which untwists the rubber core.

And another specific feature of the present invention is to provide an improved and economical method for driving a plurality of sets of spindles with a single tape.

With these and other objects in view, this invention consists in certain novel features of construction, combination and arrangement of parts to be hereinafter more fully described and claimed.

Referring to the drawings in which similar characters of reference indicate corresponding parts:

FIGURE 1 is a conventional diagrammatic view with parts in section of one form of mechanism for carrying out the invention.

FIGURE 2 is a fragmentary cross sectional view of a pair of draw rolls illustrating the mating of a rubber core with a single strand of roving.

FIGURE 3 is a modified form of the mechanism shown in FIGURE 1 illustrating two strands of roving mated with and to cover a twisted rubber core.

FIGURE 4 is a view similar to FIGURE 2 illustrating two strands of roving, covering a single twisted rubber core.

FIGURE 5 is a plan view in diagrammatic form of the new drive method for the present apparatus.

FIGURE 6 is a longitudinal cross sectional view taken along line 66 of FIGURE 5.

FIGURE 7 is an enlarged side view of an elastic yarn formed upon the apparatus of FIGURE 1, and comprises an elastic core and a cover wound helically thereupon.

In the covering of an elastic core it is imperative that the operation be carried out with very high speed and with a minimum handling of the core and roving. It is therefore important that the mechanism provided to impart the twist to the elastic core and to the roving shall operate at very high speed which is synchronized in order to give a high production of covered elastic yarn.

The bare elastic thread 10 forming the core of the elastic yarn may be formed of rubber or other rubber like material having the desired stretch characteristics.

The bare elastic thread 10 is spool wound untwisted on a spool 11 konwn in the trade as an Atwood Twister Spool. The spool 11 is provided with a bearing 12 and two thread guides 13, 14 fixed to bearing 12. Spool 11 through bearing 12 is mounted upon a spindle 15 provided with a pulley 16. Spindle 15 is rotatively supported on a fixed support 35.

The rubber thread 10 is wound upon spool 11 in an untwistecl condition and under sufficient tension to prevent the entire mass of rubber on the spool from ballooning or bulging outwardly under the high centrifugal force caused by the rapid rotation of the spool 11.

FIGURE 1 diagrammatically illustrates a conventional spinning frame having a lower creel board and upper creel board 21, an upper thread guide board 22, a lower thread guide board 23, a spinning ring rail 24, and a plurality of lower drafting nip rolls 25, 26, 27, 28 having mating upper drafting nip rolls, respectively, 30, 31, 32, 33.

The spinning mechanism used to combine the roving with the rubber core is shown as having the usual spinning spindle 34 which is journaled in a bearing mounted upon the fixed support 35 and this spindle is shown as having the usual whirl or pulley 36 driven by a belt from a rotating drum. Upon the spindle 34 is mounted a bobbin 37 upon which the finished elastic yarn 38 is wound. The bobbin 37 as is usual rotates within an opening within the spinning ring rail 24 which is traversed up and down in a well known manner to wind the yarn uniformly upon the bobbin 37. The ring rail 24 is provided with the usual ring 49 and traveler 41 with the traveler whirling around the ring as the ring rail 24 is traversed up and down. Above the upper end of the spindle 34 is provided the thread guide or pigtail 42 carried by the thread board 23 and secured thereto by the usual hinge so that it may be thrown out of the way of the bobbin to facilitate doffing.

It is found in practice that in order to produce a balanced elastic yarn the number of windings in one direction of the covering material in one inch of the relaxed elastic yarn should be approximately equal to the number of twists of the rubber core in the opposite direction in this inch of elastic yarn. This, however, is only approximate and may vary with the size of rubber core used relative to the covering material used,

The bare rubber thread 10 is twisted in accordance with the present invention by rotating the spool or package 11 about its longitudinal axis and by drawing the thread. endwise from the package and through thread guides 13, 14 upwardly in an axial direction to thread guide 42 fixed in thread board 23 and passed thread guide finger 43 fixed in thread board 23 to a selected position on lower draw nip roll 28 where the bare rubber thread 10 is grasped between nip rolls 28, 33. Stretch may also be imparted to the bare rubber core 10 as will hereinafter appear. A supply bobbin of roving consisting of a single end 51, is rotatively mounted upon a spindle 52 supported in lower creel board 211 and upper creel board 21. Roving end 51 passes through a pig tail thread guide 53 fixed to upper thread guide board 22 and to a preselected position on lower draw nip roll 28 and aligned adjacent to bare rubber thread 10 after passing through draw nip 0 rolls 25, 26, 27 and 3G, 31, 32, respectively, which perform their usual function.

FIGURE 2, illustrates the mating of bare rubber core 10 and single end roving 51 at the point of tangency of fluted lower draw or nip roll 28 and upper draw or nip roll 33.

The finished elastic yarn 38 commences at the mating of the roving 51 and the bare rubber thread 10 at the point of tangency of lower draft nip roll 28 and upper draft nip roll 33 and are spun together by the mechanism associated with bobbin 37 previously described. Bobbin 37 rotates clockwise or with a right hand twist. Spool 11 rotates in a counterclockwise or left hand direction to impart a left hand twist to the bare rubber core 10 which is untwisted by bobbin 37 as the roving covers the bare rubber core 10-.

Most of the spinning action which results in winding the textile cover about the rubber thread as a core takes place adjacent the discharge side of the draw rolls 28, 33, and since the rubber core is stiffer and has a greater contractive tendency than the drafted roving the core takes the central position and the drafted fibers are wound thereabout as a cover as clearly shown in FIGURE 7.

It will be seen from FIGURE 1 that by operating the drafting rolls 28, 33 at the proper speed relative to each other and to the let-off spool 11 and take-up package 37, the amount of twist per inch imparted to the bare rubber thread and the tension of the rubber thread between the spool 11 and the draw rolls 28, 33 may be accurately controlled. This serves to provide the proper number of twists and the proper tension of the rubber core to form a balanced elastic yarn and the amount of untwist of the elastic core and twist per inch imparted to the finished elastic yarn 38.

To control the speed of rotation of bobbin 11 and package 37 and to provide an economical drive, reference is made to FIGURES and 6, in which the spindles in the Spinning or twisting machine are arranged in rows on each side of a driving cylinder or drum, and in which a single band or tape is utilized to drive a double pair of spindles at each side of the machine.

The parts to be described are of the usual commercial construction. It is the arrangement of the parts which provide the novel results.

Spindles 34, 15, 34A, 15A, 64, 65, 64A and 65A are journaled in the respective bearings which are mounted upon fixed supports such as 35 in FIGURE 1.

Spindles 15, 15A, 65, 65A are provided with pulleys, respectively, 16, 16A, 67, 67A. Spindle 34, 34A, 64, 64A are provided, respectively, with whirls 36, 36A, 66, 66A.

The spindles are arranged with two spindles constituting a pair of spindles and with two pairs of spindles constituting a set of spindles on one side of the machine. Two sets of spindles on opposite sides of the machine forming a unit driven by a single band or endless tape.

As specifically shown in FIGURE 5 a drum 70 is driven from any convenient source of power. A band or endless tape 72 moving in the direction of arrow 74 engages whirl 36 rotating it in a clockwise direction, arrow 75, and then tape 72 engages pulley 16 rotating it counterclockwise in the direction of arrow 76. Thus, it will be seen with reference to FIGURE 1 that spool 11 is rotated counterclockwise to impart a left hand twist to bare rubber core and bobbin 37 rotates in a clockwise direction to untwist bare rubber core 10 while imparting a right hand twist to single end of roving 51 as it simultaneously covers bare rubber core 10- to produce the finished elastic yarn 38.

In like manner, endless tape 72 or belt connects pulley 16A to pulley 16, rotating pulley 16A in a counterclockwise direction, arrow 77, to rotate a spool of a bare rubber core to produce a left hand twist and then endless tape 72 connects whirl 36A to pulley 16A to rotate whirl 36A in a clockwise direction, arrow 78, thereby rotating a bobbin, taking up a finished elastic yarn, with a right hand twist. Endless tape 72 runs from whirl 36A to driven contact with drum 70. An idler pulley 86 may be provided to take up slack in endless tape 72. From drum 7t) endless tape 72 engages idler pulley 80 and runs to whirl 66A, on the opposite side of the machine from whirl 36, whereby whirl 66A is rotated in a clockwise direction, arrow 82, or with a right hand twisting motion to spindle 64A. Endless tape connects pulley 67A with whirls 66A, 66, puiley 67 and whirl 36. In this manner pulley 67A rotates spindle A in a counterclockwise direction, arrow 82, and pulley 67 in a counterclockwise direction, arrow 83 and whirl 66 in a clockwise direction, arrow 84.

It may be said that spindles 15, 34-, 15A, 34A constitute a group of spindles and that spindles 64, 64A, 65, 65A constitute another group of spindles. Said two groups of spindles being located on opposite sides of the rotating cylinder 70.

Guide pins 73, 73A, 73B and 73C may be provided in the machine frame to guide endless tape 72 in its rotational travel.

With specific reference to FIGURES 3 and 4 wherein is illustrated two ends 51A and 51B of roving or slivers of non-elastic fibers which are attenuated during passage between the nip or drafting rolls 25A thru 28A and their mating nip 0r drafting rolls 30A thru 33A which are, respectively, in nipping engagement.

The two ends 51A, 51B are drawn respectively, from supply packages or bobbins 50A, 56B and through thread guide 53A to and through the group of separate pairs of drafting nip rolls, 25A, 36A; 26A, 31A; 27A, 32A; 28A; 33A with the latter pair of nip rolls designated as the front drafting nip rolls. The two ends 51A and 51B engage the front drafting nip rolls at their meeting point or point of tangency.

It should be understood that FIGURE 3 illustrates one unit of a plurality of units which are spaced in side by side relation along the length of the machine frame.

The bare rubber core 10A is spool wound untwisted on a spool 11A provided with a bearing 12A and thread guides 13A, 14A fixed to bearing 12A. Spool 11A through bearing 12A is mounted upon spindle 15 provided with pulley 16, as previously described.

The bare rubber core 10A is pulled sidewise or endwise through thread guides 13A, 14A, and upwardly to the front drafting nip rolls 28A, 33A, whereby a twist, and stretch if desired, is imparted in said bare rubber core 10A by controlling the speed of rotation of spool 11A and the speed of rotation of front drafting nip rolls 28A, 33A, in relation to the speed of said spool 11A.

The twisted and stretched bare rubber core 10A meets the two ends 51A and 51B at the point of tangency of front nip rolls 28A, 33A.

The spinning mechanism used to combine the two ends 51A, 51B with the bare rubber core 10A is identical with the mechanism shown and described with relation to FIGURE 1. For clarity, the reference numerals of FIGURE 1 will be provided with the sufiix A when referred to in FIGURE 3.

The two attenuated ends 51A, 51B of non-elastic fibers are helically wrapped around the elongated bare rubber core 10A by the ring spinning mechanism 24A, 40A, 41A, etc., and take up bobbin 37A, with a twisting motion which is in a direction opposite to the direction of twist residing in the bare rubber core 10A at the point of tangency of front nip rolls 28A, 33A. In this manner the two slivers of non-elastic fibers are twisted about the bare rubber core 10A to cover it.

The degree of twist of the two ends 51A and 51B is determined by the ratio of the speed of rotation of take up bobbin 37A in relation to the speed of rotation of front nip rolls 28A, 33A.

It will be noted that a covered elastic threads characteristics are determined by the relation of the speed of take off spool 11A, front nip rolls 28A, 33A and take up bobbin 37A. This includes the amount of twist placed in bare rubber core 10A, the direction of twist, the stretch placed in bare rubber core 10A and the amount of untwist taken out of bare rubber core 10A by the spinning mechanism and the amount of non-elastic fiber wound around the bare rubber core A.

The only difference between the mechanism shown and described in FIGURE 1 as compared to the mechanism shown in FIGURE 3 is that FIGURE 1 illustrates one end of non-elastic fibers and FIGURE 3 shows two ends of non-elastic fibers.

Having shown and described preferred embodiments of the present invention, by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention.

What I claim is:

1. The method of making a balanced elastic yarn having a rubber core and a textile cover spun thereupon, which consists in rotating a package of a bare rubber core and pulling the bare rubber core endwise therefrom through a thread guide to a pair of nip rollers, which are in nipping engagement, to twist the bare rubber core in an uptwist motion in one direction, and advancing a textile roving through a thread guide to said pair of nip rollers and alongside of said bare rubber core where the untwisting of the bare rubber core begins to unite with the textile roving as the bare rubber core and the textile roving leave the point of engagement of said pair of nip rollers, said bare rubber core and textile roving simultaneously moving towards spinning means to thereby further spin said roving about the bare rubber core in the opposite direction to the twist in the rubber core, in a downtwist motion so as to form a helical textile cover upon the rubber core adapted to balance the twist of the rubber core.

2. The method of making a balanced elastic yarn having a rubber core and a textile cover spun thereupon, which consists in rotating a package of a bare rubber core and pulling the bare rubber core endwise therefrom through a thread guide to a pair of drafting rolls, in a set of drafting rolls, to twist the bare rubber core in an uptwist motion in one direction to a pre-selected number of turns per inch, and advancing a textile roving through a thread guide to said set of drafting rolls to attenuate said textile roving and to direct said textile roving to said pair of drafting rolls alongside said bare rubber core, said bare rubber core and textile roving simultaneously uniting by the untwisting motion of said bare rubber core at the point of tangency of said drafting rolls, said bare rubber core and roving moving towards spinning means to thereby spin said textile roving about the bare rubber core in a downtwist motion in the pre-selected number of turns per inch imparted in the bare rubber core the opposite direction to the twist in the bare rubber core to complete the untwisting of said bare rubber core so as to twist said textile roving about said bare rubber core and cover the same.

3. The method of forming a covered elastic thread which consists in rotating a spool of a bare rubber core and pulling the bare rubber core sidewise therefrom through a thread guide attached to said spool and upwardly to a pair of front drafting nip rolls of a group of separated pairs of drafting nip rolls which are in nipping engagement, to twist the bare rubber core in one direction to a pre-selected number of turns per inch, and passing a plurality of ends of loose untwisted nonelastic fibers between said group of separated pairs of drafting nip rolls, attenuating the non-elastic fibers during passage between said group of separated pairs of drafting nip rolls and simultaneously elongating the bare rubber core by passage between the pair of front drafting nip rolls, and thereafter twisting said non-elastic fibers and bare rubber core in an opposite direction and in a downtwist motion and in the same number of pre-selected turns per inch imparted to the bare rubber core to cause the non-elastic fibers to twist about said bare rubber core and cover the same.

4. The method of forming a covered elastic thread which consists in rotating a spool of a bare rubber core and pulling the bare rubber core sidewise therefrom through a thread guide attached to said spool and upwardly to a pair of front drafting nip rolls of a group of separated pairs of drafting nip rolls, which are in nipping engagement, to twist the bare rubber core in one direction to a pre-selected number of turns per inch, and passing a sliver of non-elastic fibers between said group of separated pairs of drafting nip rolls, attenuating the sliver of non-elastic fibers during passage between said group of separated pairs of drafting nip rolls and simultaneously elongating the bare rubber core by passage between the pair of front drafting nip rolls, said bare rubber core and said sliver of non-elastic fibers simultaneously moving toward ring spinning means to thereby spin said sliver of non-elastic fibers in the pre-selected number of turns per inch imparted to the bare rubber core and about the bare rubber core in the opposite direc tion to the twist in the bare rubber core and in a downtwist motion in a manner in which the untwisting of the bare rubber core simultaneously assists the ring spinning means to cause the sliver of non-elastic fibers to twist about said bare rubber core and cover the same.

References Cited UNITED STATES PATENTS 2,061,021 11/1936 Chittenden et al. 57-152 X 2,210,884 8/1940 Chittenden et a1 57--163 3,098,347 7/1963 Smith 57--163 X WILLIAM S. BURDEN, Primary Examiner. 

